Generally, it is known to individually monitor selected environmental conditions or parameters such as shock, temperature, and humidity. It is also known to individually monitor various system conditions or parameters such as vibration, strain, and tilt. The monitoring of such parameters is accomplished utilizing dedicated separate autonomous monitoring devices. These individual environmental and system monitors provide an indication of the level of such parameters to which a system is exposed. The use of these dedicated and separate monitoring devices often requires that separate power sources, sensors, data recorders, and data processors be provided for each device. Accordingly, considerable redundancy exists in the hardware required for such monitoring, and these separate monitors require individual installation, maintenance, and reading. The use of these dedicated and separate devices, e.g., including reading and/or tracking of data, can be complex, costly, bulky and space consuming, and time consuming.
It is also known to combine several environmental monitoring functions into a single monitoring system. Examples of such systems can be seen in U.S. Pat. No. 5,659,302 by Cordier titled "Process For Monitoring Equipment And Device For Implementing Said Process, " U.S. Pat. No. 5,602,749 by Vosburgh titled "Method Of Data Compression And Apparatus For Its Use In Monitoring Machinery," U.S. Pat. No. 5,481,245 by Moldavsky titled "Monitored Environment Container," and U.S. Pat. No. 5,061,917 by Higgs et al. titled "Electronic Warning Apparatus." These combination monitoring systems, however, fail to provide an accurate, cost-effective, compact, and flexible system for remotely monitoring a plurality of sensors simultaneously and with a low power consumption.
For example, due to the prohibitive costs of conventional data collection methods, highway structures are monitored at intervals measured in years. In other words, the failure to provide an accurate, cost-effective, and flexible system for monitoring a highway structure makes data related to the structure or device difficult and/or cost prohibitive to obtain. Such information or data, however, can be quite valuable to evaluation and monitoring of the structure.